[Qemu-devel] [QEMU-PPC] [PATCH 05/13] target/ppc: Add privileged message send facilities

[Suraj Jitindar Singh]

Privileged message send facilities exist on POWER8 processors and later
and include a register and instructions which can be used to generate,
observe/modify the state of and clear privileged doorbell exceptions as
described below.

The Directed Privileged Doorbell Exception State (DPDES) register
reflects the state of pending privileged doorbell exceptions and can
also be used to modify that state. The register can be used to read and
modify the state of privileged doorbell exceptions for all threads of a
subprocessor and thus is a shared facility for that subprocessor. The
register can be read/written by the hypervisor and read by the
supervisor if enabled in the HFSCR, otherwise a hypervisor facility
unavailable exception is generated.

The privileged message send and clear instructions (msgsndp & msgclrp)
are used to generate and clear the presence of a directed privileged
doorbell exception, respectively. The msgsndp instruction can be used to
target any thread of the current subprocessor, msgclrp acts on the
thread issuing the instruction. These instructions are privileged, but
will generate a hypervisor facility unavailable exception if not enabled
in the HFSCR and executed in privileged non-hypervisor state.

Add and implement this register and instructions by reading or modifying the
pending interrupt state of the cpu.

Note that TCG only supports one thread per core and so we only need to
worry about the cpu making the access.

Signed-off-by: Suraj Jitindar Singh <address@hidden>
---
 target/ppc/cpu.h                |  7 +++++
 target/ppc/excp_helper.c        | 63 +++++++++++++++++++++++++++++++++++++----
 target/ppc/helper.h             |  5 ++++
 target/ppc/misc_helper.c        | 46 ++++++++++++++++++++++++++++++
 target/ppc/translate.c          | 28 ++++++++++++++++++
 target/ppc/translate_init.inc.c | 40 ++++++++++++++++++++++++++
 6 files changed, 184 insertions(+), 5 deletions(-)

diff --git a/target/ppc/cpu.h b/target/ppc/cpu.h
index e324064111..1d2a088391 100644
--- a/target/ppc/cpu.h
+++ b/target/ppc/cpu.h
@@ -425,6 +425,10 @@ typedef struct ppc_v3_pate_t {
 #define PSSCR_ESL         PPC_BIT(42) /* Enable State Loss */
 #define PSSCR_EC          PPC_BIT(43) /* Exit Criterion */
 
+/* HFSCR bits */
+#define HFSCR_MSGSNDP     PPC_BIT(53) /* Privileged Message Send Facilities */
+#define HFSCR_IC_MSGSNDP  0xA
+
 #define msr_sf   ((env->msr >> MSR_SF)   & 1)
 #define msr_isf  ((env->msr >> MSR_ISF)  & 1)
 #define msr_shv  ((env->msr >> MSR_SHV)  & 1)
@@ -1355,6 +1359,8 @@ void cpu_ppc_set_vhyp(PowerPCCPU *cpu, 
PPCVirtualHypervisor *vhyp);
 #endif
 
 void store_fpscr(CPUPPCState *env, uint64_t arg, uint32_t mask);
+void gen_hfscr_facility_check(DisasContext *ctx, int facility_sprn, int bit,
+                              int sprn, int cause);
 
 static inline uint64_t ppc_dump_gpr(CPUPPCState *env, int gprn)
 {
@@ -1501,6 +1507,7 @@ void ppc_compat_add_property(Object *obj, const char 
*name,
 #define SPR_MPC_ICTRL         (0x09E)
 #define SPR_MPC_BAR           (0x09F)
 #define SPR_PSPB              (0x09F)
+#define SPR_DPDES             (0x0B0)
 #define SPR_DAWR              (0x0B4)
 #define SPR_RPR               (0x0BA)
 #define SPR_CIABR             (0x0BB)
diff --git a/target/ppc/excp_helper.c b/target/ppc/excp_helper.c
index beafcf1ebd..7a4da7bdba 100644
--- a/target/ppc/excp_helper.c
+++ b/target/ppc/excp_helper.c
@@ -461,6 +461,13 @@ static inline void powerpc_excp(PowerPCCPU *cpu, int 
excp_model, int excp)
         env->spr[SPR_FSCR] |= ((target_ulong)env->error_code << 56);
 #endif
         break;
+    case POWERPC_EXCP_HV_FU:     /* Hypervisor Facility Unavailable Exception 
*/
+        env->spr[SPR_HFSCR] |= ((target_ulong)env->error_code << FSCR_IC_POS);
+        srr0 = SPR_HSRR0;
+        srr1 = SPR_HSRR1;
+        new_msr |= (target_ulong)MSR_HVB;
+        new_msr |= env->msr & ((target_ulong)1 << MSR_RI);
+        break;
     case POWERPC_EXCP_PIT:       /* Programmable interval timer interrupt    */
         LOG_EXCP("PIT exception\n");
         break;
@@ -884,7 +891,11 @@ static void ppc_hw_interrupt(CPUPPCState *env)
         }
         if (env->pending_interrupts & (1 << PPC_INTERRUPT_DOORBELL)) {
             env->pending_interrupts &= ~(1 << PPC_INTERRUPT_DOORBELL);
-            powerpc_excp(cpu, env->excp_model, POWERPC_EXCP_DOORI);
+            if (env->insns_flags & PPC_SEGMENT_64B) {
+                powerpc_excp(cpu, env->excp_model, POWERPC_EXCP_SDOOR);
+            } else {
+                powerpc_excp(cpu, env->excp_model, POWERPC_EXCP_DOORI);
+            }
             return;
         }
         if (env->pending_interrupts & (1 << PPC_INTERRUPT_HDOORBELL)) {
@@ -1202,19 +1213,26 @@ void helper_msgsnd(target_ulong rb)
 }
 
 /* Server Processor Control */
-static int book3s_dbell2irq(target_ulong rb)
+static int book3s_dbell2irq(target_ulong rb, bool hv_dbell)
 {
     int msg = rb & DBELL_TYPE_MASK;
 
     /* A Directed Hypervisor Doorbell message is sent only if the
      * message type is 5. All other types are reserved and the
      * instruction is a no-op */
-    return msg == DBELL_TYPE_DBELL_SERVER ? PPC_INTERRUPT_HDOORBELL : -1;
+    if (msg == DBELL_TYPE_DBELL_SERVER) {
+        if (hv_dbell)
+            return PPC_INTERRUPT_HDOORBELL;
+        else
+            return PPC_INTERRUPT_DOORBELL;
+    }
+
+    return -1;
 }
 
 void helper_book3s_msgclr(CPUPPCState *env, target_ulong rb)
 {
-    int irq = book3s_dbell2irq(rb);
+    int irq = book3s_dbell2irq(rb, 1);
 
     if (irq < 0) {
         return;
@@ -1225,7 +1243,42 @@ void helper_book3s_msgclr(CPUPPCState *env, target_ulong 
rb)
 
 void helper_book3s_msgsnd(target_ulong rb)
 {
-    int irq = book3s_dbell2irq(rb);
+    int irq = book3s_dbell2irq(rb, 1);
+    int pir = rb & DBELL_PROCIDTAG_MASK;
+    CPUState *cs;
+
+    if (irq < 0) {
+        return;
+    }
+
+    qemu_mutex_lock_iothread();
+    CPU_FOREACH(cs) {
+        PowerPCCPU *cpu = POWERPC_CPU(cs);
+        CPUPPCState *cenv = &cpu->env;
+
+        /* TODO: broadcast message to all threads of the same  processor */
+        if (cenv->spr_cb[SPR_PIR].default_value == pir) {
+            cenv->pending_interrupts |= 1 << irq;
+            cpu_interrupt(cs, CPU_INTERRUPT_HARD);
+        }
+    }
+    qemu_mutex_unlock_iothread();
+}
+
+void helper_book3s_msgclrp(CPUPPCState *env, target_ulong rb)
+{
+    int irq = book3s_dbell2irq(rb, 0);
+
+    if (irq < 0) {
+        return;
+    }
+
+    env->pending_interrupts &= ~(1 << irq);
+}
+
+void helper_book3s_msgsndp(target_ulong rb)
+{
+    int irq = book3s_dbell2irq(rb, 0);
     int pir = rb & DBELL_PROCIDTAG_MASK;
     CPUState *cs;
 
diff --git a/target/ppc/helper.h b/target/ppc/helper.h
index 6aee195528..040f59d1af 100644
--- a/target/ppc/helper.h
+++ b/target/ppc/helper.h
@@ -657,6 +657,8 @@ DEF_HELPER_1(msgsnd, void, tl)
 DEF_HELPER_2(msgclr, void, env, tl)
 DEF_HELPER_1(book3s_msgsnd, void, tl)
 DEF_HELPER_2(book3s_msgclr, void, env, tl)
+DEF_HELPER_1(book3s_msgsndp, void, tl)
+DEF_HELPER_2(book3s_msgclrp, void, env, tl)
 #endif
 
 DEF_HELPER_4(dlmzb, tl, env, tl, tl, i32)
@@ -674,6 +676,7 @@ DEF_HELPER_3(store_dcr, void, env, tl, tl)
 
 DEF_HELPER_2(load_dump_spr, void, env, i32)
 DEF_HELPER_2(store_dump_spr, void, env, i32)
+DEF_HELPER_4(hfscr_facility_check, void, env, i32, i32, i32)
 DEF_HELPER_4(fscr_facility_check, void, env, i32, i32, i32)
 DEF_HELPER_4(msr_facility_check, void, env, i32, i32, i32)
 DEF_HELPER_FLAGS_1(load_tbl, TCG_CALL_NO_RWG, tl, env)
@@ -688,6 +691,8 @@ DEF_HELPER_FLAGS_1(load_601_rtcu, TCG_CALL_NO_RWG, tl, env)
 DEF_HELPER_FLAGS_1(load_purr, TCG_CALL_NO_RWG, tl, env)
 DEF_HELPER_FLAGS_2(store_purr, TCG_CALL_NO_RWG, void, env, tl)
 DEF_HELPER_2(store_ptcr, void, env, tl)
+DEF_HELPER_FLAGS_1(load_dpdes, TCG_CALL_NO_RWG, tl, env)
+DEF_HELPER_FLAGS_2(store_dpdes, TCG_CALL_NO_RWG, void, env, tl)
 #endif
 DEF_HELPER_2(store_sdr1, void, env, tl)
 DEF_HELPER_2(store_pidr, void, env, tl)
diff --git a/target/ppc/misc_helper.c b/target/ppc/misc_helper.c
index c65d1ade15..d7d4acca7f 100644
--- a/target/ppc/misc_helper.c
+++ b/target/ppc/misc_helper.c
@@ -39,6 +39,17 @@ void helper_store_dump_spr(CPUPPCState *env, uint32_t sprn)
 }
 
 #ifdef TARGET_PPC64
+static void raise_hv_fu_exception(CPUPPCState *env, uint32_t bit,
+                                  uint32_t sprn, uint32_t cause,
+                                  uintptr_t raddr)
+{
+    qemu_log("Facility SPR %d is unavailable (SPR HFSCR:%d)\n", sprn, bit);
+
+    env->spr[SPR_HFSCR] &= ~((target_ulong)FSCR_IC_MASK << FSCR_IC_POS);
+
+    raise_exception_err_ra(env, POWERPC_EXCP_HV_FU, cause, raddr);
+}
+
 static void raise_fu_exception(CPUPPCState *env, uint32_t bit,
                                uint32_t sprn, uint32_t cause,
                                uintptr_t raddr)
@@ -53,6 +64,17 @@ static void raise_fu_exception(CPUPPCState *env, uint32_t 
bit,
 }
 #endif
 
+void helper_hfscr_facility_check(CPUPPCState *env, uint32_t bit,
+                                 uint32_t sprn, uint32_t cause)
+{
+#ifdef TARGET_PPC64
+    if ((env->msr_mask & MSR_HVB) && !msr_hv &&
+                                     !(env->spr[SPR_HFSCR] & (1UL << bit))) {
+        raise_hv_fu_exception(env, bit, sprn, cause, GETPC());
+    }
+#endif
+}
+
 void helper_fscr_facility_check(CPUPPCState *env, uint32_t bit,
                                 uint32_t sprn, uint32_t cause)
 {
@@ -107,6 +129,30 @@ void helper_store_pcr(CPUPPCState *env, target_ulong value)
 
     env->spr[SPR_PCR] = value & pcc->pcr_mask;
 }
+
+target_ulong helper_load_dpdes(CPUPPCState *env)
+{
+    helper_hfscr_facility_check(env, HFSCR_MSGSNDP, SPR_DPDES,
+                                HFSCR_IC_MSGSNDP);
+
+    if (env->pending_interrupts & (1 << PPC_INTERRUPT_DOORBELL))
+        return 1;
+    return 0;
+}
+
+void helper_store_dpdes(CPUPPCState *env, target_ulong val)
+{
+    PowerPCCPU *cpu = ppc_env_get_cpu(env);
+    CPUState *cs = CPU(cpu);
+
+    if (val) {
+        /* Only one cpu for now */
+        env->pending_interrupts |= 1 << PPC_INTERRUPT_DOORBELL;
+        cpu_interrupt(cs, CPU_INTERRUPT_HARD);
+    } else {
+        env->pending_interrupts &= ~(1 << PPC_INTERRUPT_DOORBELL);
+    }
+}
 #endif /* defined(TARGET_PPC64) */
 
 void helper_store_pidr(CPUPPCState *env, target_ulong val)
diff --git a/target/ppc/translate.c b/target/ppc/translate.c
index fb42585a1c..2c3e83d18e 100644
--- a/target/ppc/translate.c
+++ b/target/ppc/translate.c
@@ -6537,6 +6537,30 @@ static void gen_msgsnd(DisasContext *ctx)
 #endif /* defined(CONFIG_USER_ONLY) */
 }
 
+static void gen_msgclrp(DisasContext *ctx)
+{
+#if defined(CONFIG_USER_ONLY)
+    GEN_PRIV;
+#else
+    CHK_SV;
+    gen_hfscr_facility_check(ctx, SPR_HFSCR, HFSCR_MSGSNDP, 0,
+                             HFSCR_IC_MSGSNDP);
+    gen_helper_book3s_msgclrp(cpu_env, cpu_gpr[rB(ctx->opcode)]);
+#endif /* defined(CONFIG_USER_ONLY) */
+}
+
+static void gen_msgsndp(DisasContext *ctx)
+{
+#if defined(CONFIG_USER_ONLY)
+    GEN_PRIV;
+#else
+    CHK_SV;
+    gen_hfscr_facility_check(ctx, SPR_HFSCR, HFSCR_MSGSNDP, 0,
+                             HFSCR_IC_MSGSNDP);
+    gen_helper_book3s_msgsndp(cpu_gpr[rB(ctx->opcode)]);
+#endif /* defined(CONFIG_USER_ONLY) */
+}
+
 static void gen_msgsync(DisasContext *ctx)
 {
 #if defined(CONFIG_USER_ONLY)
@@ -7054,6 +7078,10 @@ GEN_HANDLER2_E(msgclr, "msgclr", 0x1F, 0x0E, 0x07, 
0x03ff0001,
                PPC_NONE, PPC2_PRCNTL),
 GEN_HANDLER2_E(msgsync, "msgsync", 0x1F, 0x16, 0x1B, 0x00000000,
                PPC_NONE, PPC2_PRCNTL),
+GEN_HANDLER2_E(msgsndp, "msgsndp", 0x1F, 0x0E, 0x04, 0x03ff0001,
+               PPC_NONE, PPC2_ISA207S),
+GEN_HANDLER2_E(msgclrp, "msgclrp", 0x1F, 0x0E, 0x05, 0x03ff0001,
+               PPC_NONE, PPC2_ISA207S),
 GEN_HANDLER(wrtee, 0x1F, 0x03, 0x04, 0x000FFC01, PPC_WRTEE),
 GEN_HANDLER(wrteei, 0x1F, 0x03, 0x05, 0x000E7C01, PPC_WRTEE),
 GEN_HANDLER(dlmzb, 0x1F, 0x0E, 0x02, 0x00000000, PPC_440_SPEC),
diff --git a/target/ppc/translate_init.inc.c b/target/ppc/translate_init.inc.c
index 8e287066e5..46f9399097 100644
--- a/target/ppc/translate_init.inc.c
+++ b/target/ppc/translate_init.inc.c
@@ -454,6 +454,19 @@ static void spr_write_pcr(DisasContext *ctx, int sprn, int 
gprn)
 {
     gen_helper_store_pcr(cpu_env, cpu_gpr[gprn]);
 }
+
+/* DPDES */
+static void spr_read_dpdes(DisasContext *ctx, int gprn, int sprn)
+{
+    gen_hfscr_facility_check(ctx, SPR_HFSCR, HFSCR_MSGSNDP, sprn,
+                             HFSCR_IC_MSGSNDP);
+    gen_helper_load_dpdes(cpu_gpr[gprn], cpu_env);
+}
+
+static void spr_write_dpdes(DisasContext *ctx, int sprn, int gprn)
+{
+    gen_helper_store_dpdes(cpu_env, cpu_gpr[gprn]);
+}
 #endif
 #endif
 
@@ -7478,6 +7491,20 @@ POWERPC_FAMILY(e600)(ObjectClass *oc, void *data)
 #define POWERPC970_HID5_INIT 0x00000000
 #endif
 
+void gen_hfscr_facility_check(DisasContext *ctx, int facility_sprn, int bit,
+                              int sprn, int cause)
+{
+    TCGv_i32 t1 = tcg_const_i32(bit);
+    TCGv_i32 t2 = tcg_const_i32(sprn);
+    TCGv_i32 t3 = tcg_const_i32(cause);
+
+    gen_helper_hfscr_facility_check(cpu_env, t1, t2, t3);
+
+    tcg_temp_free_i32(t3);
+    tcg_temp_free_i32(t2);
+    tcg_temp_free_i32(t1);
+}
+
 static void gen_fscr_facility_check(DisasContext *ctx, int facility_sprn,
                                     int bit, int sprn, int cause)
 {
@@ -8249,6 +8276,17 @@ static void gen_spr_power8_rpr(CPUPPCState *env)
 #endif
 }
 
+static void gen_spr_power8_dpdes(CPUPPCState *env)
+{
+#if !defined(CONFIG_USER_ONLY)
+    spr_register_kvm_hv(env, SPR_DPDES, "DPDES",
+                        SPR_NOACCESS, SPR_NOACCESS,
+                        &spr_read_dpdes, SPR_NOACCESS,
+                        &spr_read_dpdes, &spr_write_dpdes,
+                        KVM_REG_PPC_DPDES, 0x0UL);
+#endif
+}
+
 static void gen_spr_power9_mmu(CPUPPCState *env)
 {
 #if !defined(CONFIG_USER_ONLY)
@@ -8637,6 +8675,7 @@ static void init_proc_POWER8(CPUPPCState *env)
     gen_spr_power8_ic(env);
     gen_spr_power8_book4(env);
     gen_spr_power8_rpr(env);
+    gen_spr_power8_dpdes(env);
 
     /* env variables */
     env->dcache_line_size = 128;
@@ -8826,6 +8865,7 @@ static void init_proc_POWER9(CPUPPCState *env)
     gen_spr_power8_ic(env);
     gen_spr_power8_book4(env);
     gen_spr_power8_rpr(env);
+    gen_spr_power8_dpdes(env);
     gen_spr_power9_mmu(env);
 
     /* POWER9 Specific registers */
-- 
2.13.6